Fig. 2.

Bid KO preserves mitochondrial integrity. a: Representative images show mitochondrial morphology in HT-22 WT cells in the presence and absence of erastin (1 µM, 2–12 h) (63x objective). Scale bar: 50 µm. b: Quantification of 500 cells counted blind to treatment of conditions of 3 independent experiments revealed time-dependent mitochondrial fission in HT-22 cells after erastin (1 µM) exposure. c: Representative images show mitochondrial morphology in HT-22 WT and Bid KO cells in the presence and absence of glutamate (5 mM, 15 h) or erastin (0.5 µM, 15 h) (63x objective). Scale bar: 50 µm. d: Quantification of 500 cells counted blind to treatment of conditions of 3 independent experiments revealed reduction of glutamate/ erastin-induced mitochondrial fission in Bid KO cells. e: After 17 h of treatment with glutamate (7 mM) or erastin (1 µM) ATP levels were measured. Bid KO prevented ATP depletion compared to WT controls (n=8/treatment condition). f, g: Measurement of the oxygen consumption rate (OCR) revealed restored basal and maximal respiration in Bid KO cells compared to WT controls after 16 h glutamate (2 mM; e) or erastin (0.25 µM; f) exposure (n=6/treatment condition). h: HT-22 Bid KO cells exhibited restored MMP measured by TMRE fluorescence compared to WT HT-22 cells after glutamate (7 mM, 19 h) or erastin (1 µM, 19 h) exposure (n=4/treatment condition). All data are given as mean +S.D. or±S.D. ##p<0.01; ###p<0.001 compared to untreated HT-22 control, ***p<0.001 compared to erastin-/ glutamate-treated HT-22 control (ANOVA, Scheffé‘s test).